#!/usr/bin/python

y = input('input: ')
x = y+1
for i in range(1, x):
    if i <= 2 or i+1 == x:
        print ' '*(x-i)+'@ '*i
    else:
        for j in range(i-2):
            space = ' '*(i+j)
        print ' '*(x-i)+'@'+space+'@'
